Sod harvester with flap control device

ABSTRACT

A sod harvester comprising a start gate, a first switch that is configured to interact with a first sensor, a second switch that is configured to internet with a second sensor, an inclined conveyor, and a rollup conveyor positioned above the second end of the inclined conveyor. The first switch is positioned between the start gate and the second switch, and the second is positioned between the first switch and the rollup conveyor. When the second sensor is activated, the rollup conveyor begins rotating. When the first sensor is activated, an encoder begins measuring distance traveled rotationally by the rollup conveyor. The rollup conveyor stops rotating when the rollup conveyor has traveled a certain distance rotationally.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of sod harvesters, and more specifically, to a sod harvester with a flap control device for consistently and neatly rolling pieces of sod so that the end of the flap is situated at roughly the same position on each roll of sod.

2. Description of the Related Art

Sod harvesters for cutting strips of sod from the ground, rolling them into sod rolls, and stacking the sod rolls onto pallets have existed for a number of years. Various sod harvester innovations have been patented, several of which relate to the rolling of sod pieces, and at least one of which has attempted to solve the same problem as the present invention. U.S. Pat. No. 7,021,584 discloses a sod roller for automatically controlling the angular position of the end or flap of a roll of sod about the roll. The latter invention differs structurally from the present invention in a number of respects, including, but not limited to, the fact that it utilizes three conveyors rather than two, and it also incorporates a sensor for measuring displacement of the transport conveyor. The transport conveyor sensor is not needed in the present invention.

When sod is sold at commercial establishments, it is typically stacked several rows high on a pallet. The more neatly the stack appears, the more likely it is to be sold. In addition, neatly stacked rolls are less likely to fall off of the pallet. In both of these respects, the placement of the end of the flap on the sod roll is important. If the end of the flap is located at roughly the same position on each of the sod rolls, this creates a more uniform appearance and adds stability to the overall configuration of the sod rolls. The present invention is designed to ensure that the end of the flap on a roll of sod is situated at roughly the same position on each roll of sod that comes off of the sod harvester.

Other innovations relating to sod rollers include U.S. Pat. No. 3,790,096 (Brouwer, 1974) (device for starting a turn in the end of a sod strip); U.S. Pat. No. 4,142,691 (Watton, 1979) (apparatus for starting a turn in a strip of sod travelling along a conveyor); U.S. Pat. No. 6,834,729 (Brouwer et al., 2004) (pre-starter for starting a turn in the end of a sod strip travelling up a conveyor); and U.S. Patent Application No. 2001/0050174 (Van Vuuren) (in one embodiment, incorporating a rolling conveyor between the receiving and discharge ends of the conveyor head for purposes of rolling cut grass sods). None of these innovations, however, is concerned with the consistent positioning of the end of the flap on the sod roll.

BRIEF SUMMARY OF THE INVENTION

The present invention is a sod harvester comprising: a start gate; a first switch that is configured to interact with a first sensor; a second switch that is configured to interact with a second sensor; an inclined conveyor with a first end and a second end; and a rollup conveyor positioned above the second end of the inclined conveyor; wherein the first switch is positioned between the start gate and the second switch; wherein the second switch is positioned between the first switch and the rollup conveyor; wherein when the second sensor is activated, the rollup conveyor begins rotating; wherein when the first sensor is activated, an encoder begins measuring distance traveled rotationally by the rollup conveyor; and wherein the rollup conveyor stops rotating when the rollup conveyor has traveled a certain distance rotationally.

In a preferred embodiment, the first sensor is activated when a trailing edge of a sod piece moves out from underneath a bottom end of the first switch and a top end of the first switch is moved into proximity with the first sensor. Preferably, the second sensor is activated when a piece of sod causes the second switch to change position so that the second switch is moved into proximity with the second sensor.

In a preferred embodiment, the bottom end of the first switch extends through a front rollup ladder, and the start gate is attached to the from rollup ladder. Preferably, the rollup conveyor is situated within a rear rollup frame. In one embodiment, the second switch is situated on the front rollup ladder. In another embodiment, the second switch is situated on the rear rollup frame.

In a preferred embodiment, the inclined conveyor and the rollup conveyor move at a same speed and in a same direction rotationally. The certain distance measured by the encoder is preferably adjustable by an operator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a sod harvester with the flap control device of the present invention.

FIG. 2 is a perspective view of the flap control device of the present invention shown with a sod piece on the inclined conveyor.

FIG. 3 is the same view shown in FIG. 2 except that two of the chains, one turn buckle, and the start gate spring have been removed for clarity.

FIG. 4A is a top view of the flap control device indicating where the section view of FIG. 4B has been taken.

FIG. 4B is a side section view of what is shown in FIG. 3.

FIG. 5 is a detail perspective view of the flap control device of the present invention shown with a leading edge of a sod piece in contact with the start gate of the flap control device and beginning to roll.

FIG. 6 is a side section view of what is shown in FIG. 5.

FIG. 7 is a first detail perspective view perspective view of the flap control device of the present invention shown with the leading (rolled) edge of the sod piece situated under the tail of the first switch and the first sensor in a deactivated position.

FIG. 8 is a side section view of what is shown in FIG. 7.

FIG. 9 is a second detail perspective view of what is shown in FIG. 7.

FIG. 10A is a top perspective view of what is shown in FIG. 7.

FIG. 10B is the same view shown in FIG. 10A except that two of the chains, one turn buckle, the start gate spring, and part of the hanging frame have been removed for clarity.

FIG. 11 is a wider perspective view of what is shown in FIG. 7.

FIG. 12A is a detail perspective view of the flap control device of the present invention shown with the leading (rolled) edge of the sod piece situated underneath the second switch and the second sensor in art activated position.

FIG. 12B is a perspective section view of what is shown in FIG. 12A.

FIG. 13 is a side section view of what is shown in FIG. 12B.

FIG. 14 is a wider perspective view of what is shown in FIG. 12A.

FIG. 15 is a side section view of the flap control device of the present invention shown with the trailing edge of the sod piece no longer situated underneath the tail of the first switch and the first sensor in art activated position.

FIG. 16 is a perspective view of the flap control device of the present invention shown with the sod roll in a fully rolled position but with the flap not yet located in the preferred position.

FIG. 17 is a side section view of what is shown in FIG. 16.

FIG. 18 is a side view of the flap control device of the present invention showing two sod rolls on the platform.

FIG. 19 is a bottom perspective view of the second switch.

REFERENCE NUMBERS

1 Sod harvester

2 Sod cutting knife

3 Inclined conveyor

4 Rollup conveyor

5 Tension roller

6 Front rollup ladder

7 Rear rollup frame

8 Sod piece

9 Start gate

10 Pivot rod

11 Chain

11 a Spring (on start gate)

11 b Spring (on first switch)

12 First switch

12 a Bottom end (of first switch)

12 b Top end (of first switch

13 First sensor

14 Second switch

15 Second sensor

16 Encoder

17 Hydraulic motor

18 Platform

19 Conveyor side rail

20 Main frame

21 Hanger frame

22 Collar (first switch)

23 Turn buckle

24 Bolt

25 Support bracket

26 Plate

27 End collar

28 Collar (second switch)

DETAILED DESCRIPTION OF INVENTION

FIG. 1 is a perspective view of a sod harvester with the flap control device of the present invention. As shown in this figure, the sod harvester 1 comprises a sod cutting knife 2, an inclined conveyor 3, and a rollup conveyor 4. The rollup conveyor 4 is situated directly on top of the upper part of the inclined conveyor 3. The conveyor side rail 19 and main frame 20 nave been removed from subsequent figures for clarity.

FIG. 2 is a first perspective view of the flap control device of the present invention shown with a sod piece on the inclined conveyor. FIG. 3 is the same view shown in FIG. 2 except that two of the chains 11, one turn buckle 23, and the start gate spring 11 a have been removed for clarity. In this figure, the sod piece 8 has not yet come into contact with the start gate 9 of the flap control device. As shown in this figure, the flap control device comprises a tension roller 5, a front rollup ladder 6, and a rear rollup frame 7. The tension roller 5 is configured to ensure that the piece of sod 8 on the inclined conveyor 3 maintains contact with the inclined conveyor 3. The front rollup ladder 6 comprises a start gate 9 that pivots on two pivot rods 10 on either end of the start gate 9.

Note that although turn buckles 23 are shown in the accompanying figures, the present invention is not limited to the use of turn buckles 23 to support the front rollup ladder 6. Any method of supporting the from rollup ladder 6 may be used. Note also that although two pivot rods 10 are shown, the start gate 9 may pivot on a single pivot rod 10 that extends from one end of the start gate 9 to the other. In addition, the present invention is not limited to the use of chains 11 to suspend the front rollup ladder 6 or the rear rollup frame 7, nor is it limited to any particular number of chains 11.

When a piece of sod 8 moves upward on the inclined conveyor 3, it first passes underneath the tension roller 5. Next, the leading edge of the piece of sod 8 comes into contact with the start gate 9, which causes the piece of sod 8 to being rolling up. A spring 11 a is used to adjust the tension on the start gate 9. Note that both the front rollup ladder 6 and the rear rollup frame 7 are preferably suspended by chains 11 so that they can move upward to accommodate the growing sod roll as it passes underneath them. The rollup conveyor 4 is attached to and situated within the rear rollup frame 7 so that it moves upward with the entire rear rollup frame 7.

A first switch 12 is attached (welded) to a collar 22 that pivots about a bolt (see FIG. 9). A spring 11 b attached to the first switch 12 and to the hanger frame 21 biases the first switch downward. The bottom end 12 a of the first switch 12 extends through the front rollup ladder 6 so that it is in a position to come into contact with a piece of sod 8 as it moves up the inclined conveyor 3. The top end 12 b of the first switch 12 is configured to interact with a first sensor 13. A second switch 14 is attached to two end collars 27 that pivot about a bolt 24 (see FIGS. 10B and 12B); the second switch 14 is configured to interact with a second sensor 15. The function of the first and second sensors 13, 15 is discussed below. Although the first and second sensors 13, 15 are depicted as proximity sensors in the drawings, any suitable type of sensor (for example, an optical sensor) may be used.

The inclined conveyor 3 and rollup conveyor 4 are preferably powered by hydraulic motors 17. During operation of the sod harvester 1, the inclined conveyor 3 is in continuous movement, whereas the rollup conveyor 4 starts and stops based on the activation or deactivation of the first and second sensors 13, 15, as explained more fully below. When the rollup conveyor 4 is on, it rotates at the same speed and in the same direction as the inclined conveyor 3 (that is, counterclockwise fern the perspective of the viewer in FIG. 4B).

FIG. 4A is a top view of the flap control device indicating where the section view of FIG. 4B has been taken. FIG. 4B is a side section view of what is shown in FIG. 3. FIG. 4B shows the relation of the first and second switches 12, 14 to the inclined conveyor 3.

FIG. 5 is a perspective view of the flap control device of the present invention shown with a leading edge of a sod piece in contact with the start gate of the flap control device and beginning to roll. FIG. 6 is a side section view of what is shown in FIG. 5; the section is taken as indicated in FIG. 4A. As shown in these two figures, the sod piece 8 starts to form a roll when the leading edge of the sod piece 8 comes into contact with the start gate 9. The start gate 9 pivots upward on the pivot rods 10 to allow the leading (and beginning to roll) edge of the sod piece 8 to pass through it. Once the sod roll starts to form, the sod piece 8 continues rolling as it moves upward on the inclined conveyor 3. The front rollup ladder 6 maintains pressure on the forming sod roll so that it stays on the inclined conveyor 3.

FIG. 7 is a perspective view of the hap control device of the present invention shown with the leading (rolled) edge of the sod piece situated under the tail of the first switch and the first sensor in a deactivated position. The turn buckle 23 and start gate spring 11 a have been, removed from this figure for clarity. FIG. 8 is a side section view of what is shown in FIG. 7; the section is taken as indicated in FIG. 4A. As shown in these two figures, the piece of sod 8 continues to roll (with the roll getting larger) as it makes its way up the inclined conveyor 3 and underneath the front rollup ladder 6. As this happens, the bottom end 12 a of the first switch 12 rises, and the top end 12 b of the first switch moves away from the first sensor 13.

FIG. 9 is a second detail perspective view of what is shown in FIG. 7. This view shows that the first switch 12 pivots on a collar 22 that rotates about a bolt 24 in a support bracket 25 that is attached (in this case, bolted) to the underside of the hanger frame 21. FIG. 10A is a top perspective view of what is shown in FIG. 7. This particular view shows more clearly how the bottom end 12 a of the first switch 12 extends through the front rollup ladder 6. FIG. 10B is the same view shown in FIG. 10A except that two of the chains 11, one turn buckle 23, the start gate spring 11 a, and part of the hanging frame 21 have been removed for clarity. FIG. 11 is a wider perspective view of what is shown in FIG. 7.

With regard to the first switch, the present invention is not limited to any particular configuration of the first switch, as long as it is positioned between the start gate 9 and the second switch 14, as long as the top end 12 b of the first switch 12 is configured to interact with a first sensor 13, and as long as the first switch 12 is configured so that the bottom end of the first switch 12 extends through the front rollup ladder 6.

FIG. 12A is a detail perspective view of the flap control device of the present invention shown whit the leading (rolled) edge of the sort piece situated underneath the second switch and the second sensor in an activated position. FIG. 12B is a perspective section view of what is shown in FIG. 12A; the section is taken as indicated in FIG. 4A. In this position, the piece of sod 8 (now a partially formed sod roll) has moved upward so that the second switch 14 is forced to rotate upward, thereby activating the second sensor 15. The trailing edge of the sod piece 8 is still underneath the front rollup ladder 6, with part of the sod piece 8 situated underneath the bottom end 12 a of the first switch 12 (see FIG. 13). As long as there is a piece of sod 8 underneath the bottom end 12 a of the first switch 12, the first sensor 13 will be deactivated. FIG. 13 is a side section view of what is shown in FIG. 12B; the section is taken as indicated in FIG. 4A. FIG. 14 is a wider perspective view of what is shown in FIG. 12A.

The present invention comprises a controller (not shown) with embedded software that controls the flap control device. When the second sensor 15 is activated, this software causes the rollup conveyor 4 to start. Specifically, the controller software causes the rollup conveyor 4 to start when the second sensor 15 is activated, the encoder 16 to begin counting when the first sensor 13 is activated, and the rollup conveyor 4 to stop when the encoder 16 counts a certain number of intervals (an interval being a measure of distance traveled rotationally by the rollup conveyor 4).

FIG. 15 is a side section view of the flap control device of the present invention shown with the trailing edge of the sod piece no longer situated underneath the tail of the first switch and the first sensor in an activated position. At this juncture, the trailing edge of the sod piece 8 has moved out from underneath the bottom end 12 a of the first switch 12, thereby causing the ton end 12 b of the first switch to move downward so that it is aligned with (in proximity to) the first sensor 13. In this position, the first sensor 13 is activated.

Activation of the first sensor 13 causes the encoder 16 to begin counting the rotational distance traveled by the rollup conveyor 4. This particular interval is preferably adjustable by the operator to ensure that the sod piece 8 continues to roll and that it is not elected onto the platform 18 until the trailing edge (or flap) of the sod roll is in the preferred position. In the position shown in FIG. 16, the sod roll has moved past the second switch 14, and the sod roll is situated between the inclined conveyor 3 and the rollup conveyor 4. The sod piece 8 continues to roll as long as it is situated between the inclined conveyor 3 and the rollup conveyor 4 and both conveyors are moving at the same speed. (As noted above, whenever the rollup conveyor 4 is on, it is preferably moving at the same speed as the inclined conveyor 3.)

FIG. 16 is a perspective view of the flap control device of the present invention shown with the sod roll in a fully rolled position but with the flap not yet located in the preferred position. FIG. 17 is a side section view of what is shown in FIG. 16. At this stage, the sod piece 8 is continuing to roll and will continue to do so until the encoder 16 reaches the end of its counting limit (that is, its measurement of the distance traveled by the rollup conveyor 4). At that point, the controller software causes the rollup conveyor 4 to stop. When the rollup conveyor 4 stops rotating, the sod roll 8 is ejected by the inclined conveyor 3 onto the platform 18.

FIG. 18 is a side view of the flap control device of the present invention showing two sod rolls on the platform. Note that the present invention ensures that each sod roll will be placed onto the platform 18 with the end of the roll (or flap) in the same position each time, even if the sod piece 8 does not start rolling as soon as the leading edge of the sod piece 8 hits the start gate 9. If the sod piece 8 does not begin to roll until the leading edge of the sod piece 8 has passed the start gate 9, then the sod roll will be smaller around by the time it hits the second switch 14 than it would have been had the sod piece 8 begun to roll at the start gate 9. In this situation, however, the sod roll will continue to turn longer (in between the inclined conveyor 3 and the rollup conveyor 4) because it will take longer tor the trailing edge of the sod piece 8 to clear the bottom end 12 a of the first switch 12, thereby triggering the encoder 16 to count and the rollup conveyor 4 to stop after a certain interval. In other words, the present invention ensures that every sod roll is the same size before the encoder 16 begins to count because the trailing edge of the sod piece 8 must clear the bottom end 12 a of the first switch 12 before the rollup conveyor 4 stops and the sod roll is ejected onto the platform 18.

FIG. 19 is a bottom perspective view of the second switch. As explained above, the second switch 14 is attached to two end collars 27 that rotate (or pivot) about a bolt 24. The bolt 24 extends through a collar 28 that is fixed to a plate 26. The plate 26 in turn is attached (welded) to the rear rollup frame 7. Note that the present invention is not limited to any particular configuration of the second switch 14, as long as it is positioned between the first switch 12 and the rollup conveyor 4, and as long as it is configured to interact with the second sensor 15. For example, the second switch may be attached to either the rear rollup frame 7, as shown in the drawings, or it may be attached to the front rollup ladder 6.

The invention described above, that is, with a second switch that starts the rollup conveyor upon being triggered by the sod roll, is an improvement over prior art (for example, the invention described in U.S. Pat. No. 7,021,584) because it provides a greater degree of accuracy in terms of starting the rollup conveyor. Although the preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. 

I claim:
 1. A sod harvester comprising: (a) a start gate; (b) a first switch that is configured to interact with a first sensor; (c) a second switch that is configured to interact with a second sensor; (d) an inclined conveyor with a first end and a second end; (e) a rollup conveyor positioned above the second end of the inclined conveyor; and (f) a controller including controller software that is configured to cause the rollup conveyor to start upon activation of the second sensor, an encoder to begin counting intervals upon activation of the first sensor, and the rollup conveyor to stop upon the counting of a certain number of intervals by the encoder, an interval being a measure of distance traveled rotationally by the rollup conveyor; wherein the first switch is positioned between the start gate and the second switch; wherein the second switch is positioned between the first switch and the rollup conveyor; and wherein the inclined conveyor is configured to eject a sod roll onto a platform upon cessation of rotation by the rollup conveyor.
 2. The sod harvester of claim 1, wherein the first sensor is configured to be activated by movement of a trailing edge of a sod piece from underneath a bottom end of the first switch and movement of a top end of the first switch into proximity with the first sensor.
 3. The sod harvester of claim 1, wherein the second sensor is configured to be activated by movement of a piece of sod to cause the second switch to change position and move into proximity with the second sensor.
 4. The sod harvester of claim 2, wherein the bottom end of the first switch extends through a front rollup ladder, wherein the start gate is attached to the front rollup ladder, and wherein the front rollup ladder is configured to maintain pressure on the sod roll on the inclined conveyor until the sod roll is ejected.
 5. The sod harvester of claim 1, wherein the rollup conveyor is situated within a rear rollup frame.
 6. The sod harvester of claim 4, wherein the second switch is situated on the front rollup ladder.
 7. The sod harvester of claim 5, wherein the second switch is situated on the rear rollup frame.
 8. The sod harvester of claim 1, wherein the inclined conveyor and the rollup conveyor are configured to move at a same speed and in a same direction rotationally.
 9. The sod harvester of claim 1, wherein the certain distance measured by the encoder is adjustable by an operator. 